class Solution:
    def findLength(self, A: List[int], B: List[int]) -> int:
        dp = [[0]*(len(B)+1) for _ in range(len(A)+1)]
        res = 0
        for i in range(1, len(A)+1):
            for j in range(1, len(B)+1):
                if A[i-1] == B[j-1]:
                    dp[i][j] = dp[i-1][j-1] + 1
                if dp[i][j] > res:
                    res = dp[i][j]
        return res